Women who took Avastin during standard chemotherapy and for up to 10 months afterward lived for about four months longer -- without signs of cancer growth -- than women who received chemotherapy alone.
Put another way, taking Avastin during and after chemo reduced the risk of cancer progression by 28% over chemo alone, says Robert A. Burger, MD, director of the Women’s Cancer Center at Fox Chase Cancer Center in Philadelphia.
Specifically, women who continued on "maintenance therapy" with Avastin, following Avastin and chemotherapy, showed no worsening of their disease for an average of 14.1 months. That compares with 10.3 months for women on chemo alone.
A third group of women in the study took Avastin only during chemotherapy. They lived an average of 11.2 months before their cancer progressed, a difference that was not significantly different than chemo alone.
Burger presented results of the study at annual meeting of the American Society of Clinical Oncology.
Avastin, which cuts off the supply of nutrient-rich blood to tumors, is already used to treat breast, lung, and colorectal cancers, typically in combination with chemotherapy.
Smaller trials showed promising activity in patients with recurrent ovarian cancer, Burger says.
The new study involved 1,873 women who had undergone surgery for newly diagnosed stage III or IV ovarian cancer, primary peritoneal cancer, or fallopian tube cancer.
One group received the standard chemotherapy combo of carboplatin and paclitaxel. Another group received Avastin plus the same chemotherapy drugs, followed by Avastin maintenance therapy. A third group received concurrent chemotherapy and Avastin, but no maintenance treatment.
Avastin Side Effects
Long-term Avastin therapy did bring more side effects. Nearly 23% of women developed moderate or serious high blood pressure, compared with 7.6% of women on chemo alone. A total of 2.6% of women developed moderate to severe bleeding, perforated intestines, or other serious gastrointestinal (GI) side effects, compared with 1.2% of women getting chemotherapy alone.
The women haven't been followed for long enough to know if long-term Avastin therapy extends lives.
The researchers have gathered data on Avastin's effect on quality on life, but the results are not ready.
So should doctors be recommending Avastin to their advanced ovarian cancer patents?
Given that cancer worsened in women on chemotherapy alone within about 10 months, "a shift to 14 months is clinically meaningful for patients," Burger tells WebMD. "This should be considered one standard option."
But Karen Lu, MD, professor of gynecologic cancers at the University of Texas M.D. Anderson Medical Center in Houston, tells WebMD that until doctors know how Avastin affects quality of life and whether it extends lives, "we don't have enough data to call it a standard of care."
For now, "each woman and her doctor will have to decide whether coming in for an IV infusion every three weeks, for an additional four months, is worth" a four-month gain in terms of stalling cancer progression, she says.
Burger notes that women who received chemotherapy prior to surgery for advanced ovarian cancer weren't included in the study. "We haven't established its safety for such patients yet," he says.
Although Avastin isn't approved for ovarian cancer, doctors can prescribe it "off-label," Burger says. When used for approved cancers, it generally costs several thousand dollars a month.
A spokesperson for Genentech, maker of the drug, says the company hopes to use the study results to seek FDA approval for use in ovarian cancer.
About 22,000 new cases of ovarian cancer will be diagnosed this year, and about 15,000 women will die from the disease, according to the American Cancer Society.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.